A number of United States patents describe devices for releasing a balloon or buoy from an object sinking at sea. In the Felix U.S. Pat. No. 4,102,296, an actuator of a marine safety signal device on a sinking vessel inflates a balloon. The balloon rises to the surface of the water and into the air above the water surface. The balloon may carry a radar reflector. The emergency signal balloon apparatus disclosed by Salmi in U.S. Pat. No. 3,425,390 also deploys a balloon into the air over a vessel.
In the Oeland et al. U.S. Pat. No. 3,123,842 a pair of inflated balloon buoys are released from an object at the bottom of the sea by a combination of chemical action and pressure sensitive response. The chemical action is provided by electrolytic disintegration of a magnesium washer. Gas pressure then moves a piston for inflating the balloon like buoys 64. The Wright U.S. Pat. No. 2,903,718 describes an automatic marker buoy secured to an outboard motor. A pressure actuated spike punctures a compressed gas container if the outboard motor sinks inflating the round marker buoy.
Two of the references, the Kirby U.S. Pat. No. 3,031,693 and the Perry U.S. Pat. No. 4,240,371 describe signal buoys or bladders for divers. The Kirby marker buoy is of interest because it is flat and rectangular in shape rather than spherical. The diver carries the marker buoy folded in a belt pouch. When the diver finds an object to be identified the marker buoy is inflated and secured to the object by a line. The flat marker buoy rises to the surface and floats on the surface. However it is of very small dimensions, apparently on the width of, for example, the diver's hand.
The Jui-Cheng Shu U.S. Pat. No. 3,280,549 describes a release mechanism using a cartridge of material expandable in water "for use in various types of safety or emergency equipment such as aboard ships". U.S. Pat. Nos. 4,586,456 and 1,771,730 are of related interest.